Can Chickens Eat Venomous Spiders? Don’t Toss Them One

Your hens might well swallow a black widow or a brown recluse some day while they’re out ranging, and you’d never know it happened. What nobody can tell you is what that spider does to a hen once it’s down. I went looking for a study that fed a venomous spider to a chicken and didn’t find one. So my answer is plain: don’t catch one and toss it to her. And the bigger risk in all this isn’t to your flock. It’s to your own hand, reaching into the woodpile after the spider.

I rewrote this page from 20 sources, and every one is listed at the bottom. The bite facts come from the Merck Veterinary Manual, from spider fact sheets and reports at four universities and from Connecticut’s experiment station, and I’ll name each one as it comes up. Eight research papers fill in the rest, from venom chemistry to a Kentucky pasture trial. This page used to tell a story about a barred rock called Ol’ Bertie and a black widow. I can’t vouch for any of it, so it’s gone. So are the numbers I couldn’t find in a source, like a hen’s stomach acid running a pH of around 3 to 5 and a widow’s bite carrying less than 20 micrograms of venom, with 25 widows’ worth adding up to just 1 mg. The claims that some breeds handle venom better than others, that hens build up a tolerance, and that no venom could ever reach the eggs or meat are gone too.

A word on the photos. None of them shows a hen eating a spider, because I couldn’t find a real one I’d trust. The black widow up top is standing over her egg sac. Alejandro Santillana photographed her for the Insects Unlocked project at the University of Texas at Austin, and I trimmed off the project’s printed label to make it a tall picture. The brown recluse further down is Matt Britt’s, an adult male photographed in 2008. The rest are everyday stuff: hens, a woodshed and two orb webs.

The short version.

• Nobody has tested what a widow or a recluse does inside a chicken. I couldn’t find a single study that tried it.
• Don’t catch one to feed her. You’re the one who’d get bitten, and nothing I read gives a hen a reason to eat one.
• Widow venom carries a toxin built for animals with backbones. In a 1983 lab test it made a chick’s neck muscle contract and stay that way. That was the purified toxin on a muscle, not a hen that ate a spider.
• Your flock won’t clean spiders out for you. In a Kentucky pasture trial, ground spiders were 2.4 times as common where broilers were stocked thickest as where there were no birds at all.
• Wear gloves in the woodpile and the shed, and shake out gloves and boots that have sat a while.
• If a hen acts off after a day of poking around the woodpile, call a vet who sees poultry. We aren’t vets.

The Two Spiders People Mean

When folks ask this, they’ve usually got two spiders in mind. Merck’s veterinary manual says the spiders in the US that can cause clinical envenomation come from two groups, the widows (Latrodectus) and the recluses, mostly Loxosceles. The black widow and the brown recluse are the famous ones.

A female widow runs 8 to 13 mm long, going by Merck (the males are just 3 mm), and she wears a red or orange hourglass on the underside of her belly. Washington State puts an adult female at about 1 1/2 inches across with her legs. Two catches, though, and they’re kinda important. Immature females might not have the hourglass yet, Merck says. And on the northern black widow, Connecticut’s experiment station says the hourglass is “broken” in the center. The widow in the photo shows only a thin red mark at her side, since the hourglass is underneath her.

The brown recluse is a plain tan spider, and its venom works a different way. Merck names an enzyme called sphingomyelinase D as “the main dermonecrotic factor”, which is the part that kills skin. Widow venom goes after nerves instead. Connecticut’s fact sheet calls it “extremely potent neurotoxic venom”, and Merck says a toxin called alpha-latrotoxin “is the main component of the venom”.

Both are shy, which matters later. Widows “usually bite only when accidentally touched”, per Merck’s page for pet owners. Kentucky’s entomologists say plainly that the brown recluse is “not aggressive”.

What a Hen Actually Catches

Give a hen some ground and she’ll hunt it, as you’ve probably seen. Merck’s backyard poultry chapter says birds with outdoor access “supplement their diet by foraging and eating insects”. Colorado State says the same about free-range chickens. And Oregon State’s guide to chicken tractors says chickens “scratch the soil in search of insects, seeds, young plant shoots and other food”.

How much do they get? A University of Kentucky team summed up an older study where researchers cut open the crops of free-range chickens working an apple-and-potato planting. Those crops held helpful beetles and pest beetles alike, and Japanese beetles turned up in 75% of them.

Spiders didn’t make that summary. Honestly, I couldn’t find anybody who counted spiders in a chicken’s crop, either. I’d still bet a ranging hen grabs a spider when one crosses her path, same as she grabs a beetle. That’s my guess, not a finding.

But a widow isn’t sitting out on open ground. Ohio State’s Ohioline lists where widows build their webs: “in woodpiles, rubble piles, under stones, in hollow stumps, and in rodent burrows”. Recluses are night spiders that hide in “undisturbed places in and around buildings”, Merck says. So a hen meets one of these where she pokes her head into a pile or under a board. Keep that in mind, because that’s also where you put your hand.

Nobody Has Tested It in a Chicken

Here’s where the science runs out. I searched PubMed for anything that fed a widow or a recluse, or their venom, to a chicken, and nothing came up. The closest I got is a paper from 1973, more than 50 years ago, in the journal Toxicon. It’s titled “Toxicity of Latrodectus mactans tredecimguttatus venom on frog and birds”. Tredecimguttatus is the European black widow, going by Merck. PubMed has no abstract for it and I couldn’t read past the title. So I can’t tell you which birds it used, or how the venom got into them, or what happened to them.

What we do know comes in pieces.

Widow venom has separate toxins for separate prey. A 2007 review counts five insecticidal toxins found in it so far, plus “a vertebrate-specific neurotoxin”, alpha-latrotoxin. A chicken has a backbone, so that last one is built for her kind.

Chicken tissue does answer to it. In a 1983 lab test, purified alpha-latrotoxin “caused a sustained contraction of the chick biventer cervicis muscle”, a muscle in the neck. The researchers used that response as a yardstick for how strong a batch of toxin was. But that was the toxin acting on a muscle in a lab. It says nothing about a hen that swallows a spider.

Swallowing isn’t the same as a bite. Merck spells out that envenomation happens “via the injection of venom through fangs”. A swallowed spider goes down the gut instead, through the proventriculus, which the poultry folks at extension.org call the true stomach. Hydrochloric acid and enzymes like pepsin get added there and start breaking the food down.

It’s tempting to stop right there and say her stomach acid takes care of it. The old version of this page did. Nobody has shown that, though. And in insects at least, some venoms still work when they’re swallowed. A spider toxin called Hv1a kills insect pests when it’s injected, but it “has limited oral toxicity”, a 2012 study found. Fed to cabbage moth caterpillars in droplets, Hv1a alone didn’t make a significant dent in their growth or survival. Then a 2023 lab screen fed 82 venoms to moth larvae and mealworms, plus fruit flies, and found “18 venoms from spiders and snakes” with high oral toxicity. That’s insects, not chickens. Still, it’s enough that I wouldn’t lean on a hen’s gut to make venom harmless, and I don’t think you should either.

Species differ a lot. Merck says dogs and their kin “have some resistance” to widow toxin, while cats and horses, and guinea pigs too, are highly susceptible. Chickens aren’t on that list either way, and the chapter doesn’t mention poultry.

Our Can Chickens Eat It? checker doesn’t rate spiders either. None of the official sources it uses rules on them, so it won’t guess. Neither will I, and turns out that’s the honest answer here.

More Hens, More Spiders?

Some folks hope a free-range flock will clear the spiders out of the yard. A trial that the University of Kentucky team I mentioned ran for 2 years says don’t count on it. They ran broilers in chicken tractors (floorless pens you move across the ground, 8 ft by 8 ft at the base) on a cover crop at two stocking rates. One gave each bird about 102 square feet of pasture and the other about 51 square feet. They used Red Rangers the first year and Cornish Rock Crosses the second, brooded to 3 weeks of age before they went out, and they caught bugs in 216 pitfall traps.

On the ground, the birds didn’t knock the spiders back. Spiders were 2.4 times as abundant in the high-density plots as in the plots with no poultry. Dung beetles were up 47 times and rove beetles 3.5 times.

The birds did cut down the bugs living up on the plants. They flattened the cover crop fast, too: the high-density pens had 7.8 times less of it than the control after just 1 to 3 days. The authors put that down to the birds eating and trampling the cover crop, and to “direct consumption of arthropods”. As for the ground, they say adding poultry “may also stimulate the soil and ground-foraging arthropod food webs”, and they point to the manure as one way that happens. More manure, more critters, and more for spiders to eat. That last bit is my reading of it, not theirs.

These were meat birds in moving pens, not a laying flock in a backyard run. But I’d still take the hint. Your hens are no spider control.

The Bite Risk Is Yours, Not Hers

Spiders do bite farm animals now and then. Merck notes outbreaks of widow poisoning in livestock and horses in southern Russia, and in Spain and Chile too. But around a backyard coop, I’d worry about the person stacking firewood first. That’s probably you. Look at where widows live. Washington State lists firewood, old lumber, dry crawl spaces and rock piles, plus outbuildings and hay bales. The University of Georgia’s field report says “Widow spiders also like unheated sheds and barns”. A coop with a woodpile beside it fits that list pretty well, by my reckoning.

Georgia’s report puts it at about 4 percent to 5 percent of people bitten who have a severe reaction or die. So this part is worth taking seriously.

And bites happen when a spider gets pressed against you. Kentucky’s recluse sheet says “Most bites occur in response to body pressure”, when a spider is trapped against bare skin. Others happen while moving stored items or pulling on clothing a spider has picked for its daytime hideout. The same sheet says a recluse has “very small fangs and cannot bite through clothing”. That’s your best tool right there.

So here’s what the fact sheets tell you to do:

• Wear gloves. Washington State says to “collect wood with gloves”. Georgia’s Elmer Gray put it flatly: “avoidance and personal protection, such as work gloves, are the only guaranteed techniques for bite prevention”.
• Gloves or boots that have sat in the shed a long time? Connecticut says “turn them inside out or shake them out thoroughly before wearing”.
• Wear long sleeves, too, when you sort through boxes or stored stuff, per Kentucky.

If you get bitten by something you think was a recluse, Kentucky says to ice the bite, raise the bitten spot and get medical attention right away. Don’t wait it out. The sheet says people often don’t notice the bite until 3 to 8 hours later, when the spot may turn red and swollen.

If you think a hen got bitten, you probably won’t catch the spider. Merck points out a spider is unlikely to stick around for the 30 minutes to 6 hours that signs take to develop. In the animals Merck covers, a widow bite brings muscle cramps near the bite 1 to 2 hours later, with worse signs expected within 8 hours. That’s one more reason to have a vet lined up before you need one. Colorado State says “Flock owners must have an identified veterinarian in their area that can diagnose and treat chickens”.

Telling a Recluse From the Brown Spiders That Aren’t

Before you panic over a brown spider in the coop, check where you live. Merck puts the brown recluse’s range from central Texas to Kansas, then east through Missouri as far as Kentucky and Tennessee, plus Alabama and Georgia. It reaches into parts of Nebraska and Illinois, of Iowa and Indiana, and of Ohio. Kentucky’s sheet says “Recluse spiders are rare outside their native range”.

A 2005 study by R. S. Vetter put that to the test. Vetter offered online to identify any spider people thought was a brown recluse, and 1,773 arachnids came in from 49 states. From 25 of the 29 states completely or almost completely outside the recluse range, not one recluse came in. His conclusion was that recluses are “virtually limited to their known distributions”.

If you are in recluse country, here’s what Kentucky’s entomologists tell you to look for:

• A dark violin-shaped mark on its back, with the neck of the violin pointing toward the rear. It shows on adults, but it’s sometimes less obvious on younger spiders.
• Six eyes in three pairs, where most other spiders have 8. Seeing them “requires a good quality hand lens”, the sheet says.
• Abdomen and legs all one color, with no stripes, bands or mottling. The legs are long and thin, with no conspicuous spines.

Matt Britt’s photo shows the plain tan body and the darker violin pretty well. Even so, Kentucky warns that “Many harmless brown spiders are mistaken for the brown recluse”. The sheet’s advice is to have a suspect confirmed by an entomologist or a knowledgeable pest control firm. Georgia’s report adds that your local extension agent should be able to help with the ID.

Should You Toss Them a Spider on Purpose?

Not a widow or a recluse, no. Catching one is how you get bitten, and nobody has tested what it does inside a hen. There’s no feeding reason I could find to take that chance.

The everyday spiders in your run? I’d pretty much leave them be. Kentucky’s entomologists say “Most spiders are harmless and in fact beneficial because they prey upon flies and other pests”. Ohioline says much the same. Some even work the henhouse for you. A 2020 study of the bugs living in henhouses found a linyphiid spider among the predators of the poultry red mite.

If your birds are already chasing things that fight back, I’ve written two of those up the same way, fire ants and frogs and toads. For the foods that are a flat no, there’s what you shouldn’t feed chickens.

And if a hen acts off after a day spent under the woodpile, call a vet who sees poultry. We aren’t vets, and nothing here replaces one.

Sources

• Andras Laszlo Nagy, Merck Veterinary Manual: Spider and Scorpion Bites and Stings to Animals.
• Merck Veterinary Manual, for pet owners: Spider Bites.
• Yuko Sato, Merck Veterinary Manual: Management of Backyard Poultry.
• Colorado State University Extension: Raising Poultry the Organic Way, Disease Control and Feeding.
• B. Miller, T. Witmer and L. Brewer, Oregon State University Extension: Chicken Tractors, Moveable Flocks Help Manage Orchard Pests (EM 9320, 2021).
• Small and Backyard Poultry, extension.org: Avian Digestive System.
• K. Garcia and colleagues, University of Kentucky: Net effects of pasture-raised poultry on arthropod communities driven by top-down and bottom-up forces in a mixed-cover crop system (Frontiers in Sustainable Food Systems, 2023).
• M. Maroli, S. Bettini and B. Panfili: Toxicity of Latrodectus mactans tredecimguttatus venom on frog and birds (Toxicon, 1973; title only, no abstract online).
• M. C. Tzeng and S. S. Tian: Use of chick biventer cervicis muscle in the bioassay of alpha-latrotoxin from black widow spider venom (Toxicon, 1983).
• A. Rohou, J. Nield and Y. A. Ushkaryov: Insecticidal toxins from black widow spider venom (Toxicon, 2007).
• E. C. Fitches and colleagues: Fusion to snowdrop lectin magnifies the oral activity of insecticidal ω-Hexatoxin-Hv1a peptide by enabling its delivery to the central nervous system (PLoS One, 2012).
• P. B. Oparin, S. S. Nikodimov and A. A. Vassilevski: Venoms with oral toxicity towards insects (Toxicon, 2023).
• R. S. Vetter: Arachnids submitted as suspected brown recluse spiders (Araneae: Sicariidae): Loxosceles spiders are virtually restricted to their known distributions but are perceived to exist throughout the United States (Journal of Medical Entomology, 2005).
• G. Zriki, R. Blatrix and L. Roy: Predation interactions among henhouse-dwelling arthropods, with a focus on the poultry red mite Dermanyssus gallinae (Pest Management Science, 2020).
• Michael F. Potter, University of Kentucky Entomology: Brown Recluse Spider (ENTFACT-631).
• Michael F. Potter, University of Kentucky Entomology: Eliminating Spiders around Homes and Buildings (ENTFACT-623).
• Washington State University Pestsense: Widow spiders.
• Stephanie Schupska, University of Georgia CAES Field Report: Widow spiders, why gardeners wear work gloves.
• Katherine Dugas, The Connecticut Agricultural Experiment Station: Northern Black Widow Spider.
• Ohio State University Extension, Ohioline: Spider Bites for Trainers and Supervisors (AEX-892.2.71).

Sources checked October 28, 2026. The calls on not feeding a venomous spider, on where a hen meets one and on who’s more likely to get bitten are mine, from these sources. We aren’t vets. If a hen acts off, or you think something bit her, call a vet who sees poultry.